I play a lv30 paladin (divinate19) and with his doubled spell duration, EDM, DS it is already a very strong build.
(The doubled duration last long enough for dungeons like the vault.)
And he's an excellent turner.

Now, if one makes a lv30 paladin (divinate19/S.channeler10), it can get all the above build has and all the Solar channeler goodies on top of that - without any further cost !